UCC5611
18 LINE 3-5 VOLT SCSI ACTIVE TERMINATOR,
REVERSE DISCONNECT
SLUS348A MARCH 1997 REVISED NOVEMBER 2000
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D
Complies with SPI-2 and SPI-3 Standards
D
2.75-V to 7-V Operation
D
1.8-pF Channel Capacitance during
Disconnect
D
1-
A Supply Current in Disconnect Mode
D
110-
/2.5-k Programmable Termination
D
Completely Meets SCSI Hot Plugging
D
650-mA Sourcing Current for Termination
D
+400-mA Sinking Current for Active
Negation Drivers
D
Trimmed Termination Current to 4%
D
Trimmed Impedance to 7%
D
Current Limit and Thermal Shutdown
Protection
description
The UCC5611 provides 18 lines of active termination for a SCSI (Small Computer Systems Interface) parallel
bus. The SCSI standard recommends active termination at both ends of the cable segment.
The UCC5611 is ideal for high performance 3.3-V SCSI systems. The key features contributing to such
low-operating voltage are the 0.1-V drop-out regulator and the 2.75-V reference. During disconnect the supply
current is typically only 1
A, which makes the IC attractive for battery powered systems.
The UCC5611 is designed with an ultra-low channel capacitance of 1.8 pF, which eliminates effects on signal
integrity from disconnected terminators at interim points on the bus.
The UCC5611 can be programmed for either a 110-
or 2.5-k
termination. The 110-
termination is used for
standard SCSI bus lengths and the 2.5-k
termination is typically used in short bus applications. When driving
the TTL compatible DISCNCT pin directly, the 110-
termination is connected when the DISCNCT pin is driven
high, and disconnected when low. When the DISCNCT pin is driven through an impedance between 80 k
and
150 k
, the 2.5-k
termination is connected when the DISCNCT pin is driven high, and disconnected when
driven low.
block diagram
UDG-94131-1
Copyright
2000, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
UCC5611
18 LINE 3-5 VOLT SCSI ACTIVE TERMINATOR,
REVERSE DISCONNECT
SLUS348A MARCH 1997 REVISED NOVEMBER 2000
2
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
description (continued)
The power amplifier output stage allows the UCC5611 to source full termination current and sink active negation
current when all termination lines are actively negated.
The UCC5611 is pin for pin compatible with Texas Instrument's other 18-line SCSI terminators, except that
DISCNCT is now active low, allowing lower capacitance and lower voltage upgrades to existing systems. The
UCC5611, as with all of Texas Instrument terminators, is completely hot pluggable and appears as high
impedance at the terminating channels with V
TRMPWR
= 0 V or open.
Internal circuit trimming is utilized, first to trim the 110-
termination impedance to a 7% tolerance, and then most
importantly, to trim the output current to a 4% tolerance, which maximizes noise margin.
Other features include thermal shutdown and current limit.
This device is offered in low thermal resistance versions of the industry standard 28-pin wide body SOIC and
28-pin PLCC.
3 2 1
13 14
5
6
7
8
9
10
11
LINE6
LINE5
LINE4
LINE3
LINE2
LINE1
DISCNCT
LINE12
LINE13
LINE14
LINE15
LINE16
LINE17
LINE18
4
15 16 17 18
GND*
GND*
GND*
GND*
GND*
GND*
LINE1
1
LINE10
REG
TRMPWR
QP PACKAGE
TOP VIEW
28 27 26
25
24
23
22
21
20
19
12
GND*
LINE9
LINE8
LINE7
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
DISCNCT
LINE1
LINE2
LINE3
LINE4
LINE5
GND*
GND*
GND*
LINE6
LINE7
LINE8
LINE9
TRMPWR
GND
LINE18
LINE17
LINE16
LINE15
LINE14
GND*
GND*
GND*
LINE13
LINE12
LINE11
LINE10
REG
DWP PACKAGE
TOP VIEW
* DWP package pin 28 serves as signal ground;
pins 7, 8, 9, 20, 21, 22 serve as heatsink/ground.
* QP package pins 12-18 serve as both heatsink
and signal ground.
AVAILABLE OPTIONS
TJ
PACKAGED DEVICES
TJ
SOIC (DWP)
PLCC (QP)
0
C to 70
C
UCC5611DWP
UCC5611QP
Available tape and reeled. Add TR suffix to device type to order quantities of 1000 devices per reel.
UCC5611
18 LINE 3-5 VOLT SCSI ACTIVE TERMINATOR,
REVERSE DISCONNECT
SLUS348A MARCH 1997 REVISED NOVEMBER 2000
3
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
absolute maximum ratings over operating free-air temperature (unless otherwise noted)
Termpwr voltage
7 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signal line voltage
0 V to 7 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regulator output current
Self-regulating
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature, T
stg
65
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating junction temperature, T
J
55
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature (soldering, 10 Sec.)
300
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Unless otherwise specified all voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. Consult
Packaging Section of Interface Products Data Book (TI Literature Number SLUD002) for thermal limitations and considerations of packages.
recommended operating conditions
Termpwr voltage
2.75 V to 5.25 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signal line voltage
0 V to 5 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disconnect input voltage
0 V to Termpwr
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
electrical characteristics, these specifications apply for T
A
= 0
C to 70
C. TRMPWR = 3.3 V,
DISCNCT = 3.3 V, R
DISCNCT
= 0
. T
A
= T
J
, (unless otherwise stated)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Supply Current Section
Termpwr supply current
All termination lines = open
1
2
mA
Termpwr supply current
All termination lines = 0.2 V
415
435
mA
Power down mode
DISCNCT = 0V
0.5
5
A
Output Section (110
Terminator Lines)
Terminator impedance
See Note 4
102.3
110
117.7
Output high voltage
TRMPWR = 3 V,
See Note 1
2.5
2.7
3.0
V
VLINE = 0.2 V,
TJ = 25
C
25.4
23
22.1
mA
VLINE = 0.2 V
25.4
23
21
mA
Max output current
VLINE = 0.2 V,
TRMPWR = 3 V,
TJ = 25
C,
See Note 1
25.4
23
20.2
mA
VLINE = 0.2 V,
TRMPWR = 3 V,
See Note 1
25.4
23
19
mA
VLINE = 0.5 V
22.4
mA
Output leakage
DISCNCT = 0 V,
TRMPWR = 0 V to 5.25 V
10
400
nA
Output capacitance
DISCNCT = 0 V,
DWP package,
See Note 2,
See Note 3
1.8
2.5
pF
Output Section (2.5 k
Terminator Lines) (RDISCNCT = 80 k
)
Terminator impedance
2
2.5
3
k
Output high voltage
TRMPWR = 3 V,
See Note 1
2.5
2.7
3.0
V
Max output current
VLINE = 0.2 V
1.4
1
0.7
mA
Max output current
VLINE = 0.2 V,
TRMPWR = 3 V,
See Note 1
1.5
1
0.6
mA
Output leakage
DISCNCT = 0 V,
TRMPWR = 0 to 5.25 V
10
400
nA
Output capacitance
DISCNCT = 0 V,
DWP package,
See Note 2,
See Note 3
1.8
2.5
pF
NOTES:
1. Measuring each termination line while other 17 are low (0.2 V).
2. Ensured by design. Not production tested.
3. Output capacitance is measured at 0.5 V.
4. Tested by measuring IOUT with VOUT = 0.2 V and VOUT = VREG 0.1 V then calculating the impedance.
UCC5611
18 LINE 3-5 VOLT SCSI ACTIVE TERMINATOR,
REVERSE DISCONNECT
SLUS348A MARCH 1997 REVISED NOVEMBER 2000
4
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
electrical characteristics, these specifications apply for T
A
= 0
C to 70
C. TRMPWR = 3.3 V,
DISCNCT = 3.3 V, R
DISCNCT
= 0
. T
A
= T
J
, (unless otherwise stated)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Regulator Section
Regulator output voltage
5.25 V > TRMPWR > 3 V
2.5
2.7
3.0
V
Drop out voltage
All termination lines = 0.2 V
0.1
0.2
V
Short circuit current
VREG = 0 V
800
650
450
mA
Sinking current capability
VREG = 3 V
200
400
800
mA
Thermal shutdown
See Note 2
170
C
Thermal shutdown hysteresis
See Note 2
10
C
Disconnect Section
Disconnect threshold
RDISCNCT = 0 & 80 k
0.8
1.5
2.0
V
Input current
DISCNCT = 3.3 V
30
50
A
NOTES:
2. Ensured by design. Not production tested.
APPLICATION INFORMATION
UDG-94132
Figure 1. Typical SCSI Bus Configurations Utilizing a UCC5611 Device
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pertaining to warranty, patent infringement, and limitation of liability.
TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in
accordance with TI's standard warranty. Testing and other quality control techniques are utilized to the extent
TI deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily
performed, except those mandated by government requirements.
Customers are responsible for their applications using TI components.
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safeguards must be provided by the customer to minimize inherent or procedural hazards.
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Copyright
2000, Texas Instruments Incorporated
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